A vehicle driving cooperative control method and system based on road segment information analysis

Abstract

The present application relates to vehicle driving cooperative control technical field, disclose a kind of vehicle driving cooperative control method and system based on road section information analysis, comprising: according to road section geometric characteristics and vehicle state parameter calculation stress expected gradient, according to this establish working condition mutation point and predict control reference time;Combining brake pipe temperature, mass transfer delay, gap elimination time and bus delay calculation real pressure building time delay, compare moment response time delay to establish first trigger time and second trigger time;Respectively at first trigger time and second trigger time control hydraulic brake execution unit pre-pressurization and driving torque adjustment unit and reduce output torque, so that time delay end point coincides at control reference time, the present application eliminates the torque vacuum and parasitic resistance generated by the response of subsystem asymmetric, reduce longitudinal acceleration impact.

Description

Technical Field

[0001] This invention belongs to the field of vehicle driving cooperative control technology, and in particular relates to a vehicle driving cooperative control method and system based on road segment information analysis. Background Technology

[0002] Currently, with the integration of connected sensing infrastructure and vehicle-side control units, predicting driving status and adjusting the coordinated action of multiple subsystems through road segment geometric features has become an important way to improve dynamic stability. The mainstream solution usually uses sensors to obtain the trend of road segment slope and adhesion coefficient changes, thereby converting the variation characteristics into force requirements and distributing them to the power unit and braking mechanism to maintain the balance of the whole vehicle in the working condition boundary area. This cross-domain scheduling solution relies on the assumption of control cycle alignment and does not consider the inconsistency in response characteristics and mass transfer resistance between the drive and braking subsystems. The torque unloading response of the electric drive circuit is on the microsecond scale, while the brake line has fluid resistance and pump valve hysteresis when transmitting oil, resulting in the hydraulic pressure build-up response exhibiting a high-dimensional nonlinear time delay. This causes the driving torque decay rate and the braking pre-pressure build-up action timing to be misaligned, generating torque vacuum or parasitic torque interference in the transition area, causing transient wheel slippage and longitudinal acceleration impact of the vehicle body.

[0003] Traditional solutions typically employ constant time delay feedforward for static compensation. However, hydraulic mass transfer delay is severely constrained by viscosity temperature drift caused by temperature, and the bus load is in a state of dynamic jitter. A single constant mechanism cannot adapt to varying operating conditions, and blind feedforward may even prematurely introduce parasitic frictional resistance. The aforementioned improvements to the physical characteristics at the hardware level have not fundamentally solved the problem of cross-domain timing misalignment. The control method also has shortcomings in dealing with asymmetric time delays. For example, Chinese invention patent application CN121515926A discloses a method for coordinated control of braking force in electro-hydraulic hybrid vehicles based on the rate of change of braking demand, which calculates the braking torque change based on the brake pedal opening. The braking force distribution is determined by a nonlinear mapping module. This scheme implicitly relies on the driver's clear braking intention and pedal operation as a reactive triggering feature. When the vehicle faces complex conditions such as drastic changes in road geometry or sudden changes in road adhesion coefficient, there is a fundamental mismatch between its preset premise and the actual dynamic boundary conditions. Due to the lack of the ability to anticipate the road conditions ahead, it is a lagging passive adjustment. In the instantaneous state of rapidly increasing braking demand, the motor torque is quickly unloaded, and the inherent fluid mass transfer temperature drift delay and friction pair mechanical clearance elimination delay of the hydraulic pipeline cannot be synchronously coordinated when the wheel reaches the point of sudden change in road conditions, introducing torque vacuum or parasitic resistance impact.

[0004] Therefore, the technical problem to be solved by this invention is how to identify the boundary of abrupt working conditions based on the expected force gradient established by the geometric characteristics of the road section ahead, and couple the pipeline mass transfer temperature drift and bus network dynamic jitter to rearrange the cross-domain action timing to eliminate the mechanical clearance of the friction pair, and combine the state feedback residual to update the control parameters online to offset the wear and deterioration of the components. Summary of the Invention

[0005] This invention aims to solve the problem of identifying abrupt working condition boundaries based on the expected stress gradient established by the geometric characteristics of the road section ahead, and coupling pipeline mass transfer temperature drift and bus network dynamic jitter to rearrange cross-domain action timing to eliminate mechanical clearance of friction pairs, and combining state feedback residuals to update control parameters online to offset component wear and deterioration.

[0006] In this technical solution, a vehicle driving cooperative control method based on road segment information analysis includes the following steps:

[0007] Step S101: Obtain the segmented geometric feature parameters of the target road segment ahead and the driving state parameters of the current vehicle, and calculate the expected force gradient of the target road segment ahead relative to the current vehicle position based on the segmented geometric feature parameters and the driving state parameters. Step S102: When the expected gradient of the force is greater than the first calibration threshold, the road section working condition change point is established, and the control reference time when the wheel touches the road section working condition change point is predicted based on the current vehicle speed. Step S103: Based on the control reference time, according to the real-time temperature of the brake pipeline of the hydraulic brake actuator and the calibrated fluid mass transfer delay constant, the actual pressure build-up delay of the hydraulic brake actuator is calculated in combination with the brake gap elimination time and the bus transmission delay. The torque response delay of the drive torque adjustment unit is compared with that of the drive torque adjustment unit to establish the first trigger time for eliminating the brake friction pair gap and the second trigger time for adjusting the output torque. Step S104: At the first trigger moment, control the hydraulic braking actuator to perform braking pre-pressure build-up, and at the second trigger moment, control the drive torque adjustment unit to reduce the output torque, so that the end point of the actual pressure build-up delay of the hydraulic braking actuator and the end point of the torque response delay of the drive torque adjustment unit coincide at the control reference moment.

[0008] Preferably, after the vehicle enters the point of sudden change in road conditions, the following steps are also included: Step S201, obtain the current vehicle's true longitudinal acceleration and calculate the longitudinal residual value between the true longitudinal acceleration and the expected longitudinal acceleration; Step S202, when the longitudinal residual value is greater than the second calibration threshold, adjust the torque attenuation slope of the drive torque adjustment unit and the wheel cylinder pressure value of the hydraulic brake execution unit until the longitudinal residual value is less than or equal to the second calibration threshold.

[0009] Preferably, the method further includes the following steps: step S301, sampling the expected force gradient at a fixed period and monitoring the oscillation amplitude of the expected force gradient on the time axis; step S302, when the oscillation amplitude is greater than the third calibration threshold in multiple consecutive sampling periods, stabilizing the torque attenuation slope of the driving torque adjustment unit within the first calibration range, and stabilizing the wheel cylinder pressure of the hydraulic brake actuator within the second calibration range.

[0010] Preferably, the method for calculating the actual pressure build-up delay in step S103 includes the following steps: Step S1031, determining the hydraulic viscosity correction coefficient based on the real-time temperature of the brake pipeline of the hydraulic brake actuator, wherein the hydraulic viscosity correction coefficient is inversely proportional to the real-time temperature; Step S1032, multiplying the calibrated fluid mass transfer delay constant by the hydraulic viscosity correction coefficient to obtain the corrected fluid mass transfer delay; Step S1033, adding the corrected fluid mass transfer delay to the brake gap elimination time and the bus transmission delay to obtain the actual pressure build-up delay.

[0011] Preferably, the segmented geometric feature parameters in step S101 include the slope variation rate and the road surface adhesion coefficient variation rate. The method for determining the road segment condition change point in step S102 includes the following steps: Step S1021, weighted summation of the slope variation rate and the road surface adhesion coefficient variation rate to obtain the stress disturbance parameter; Step S1022, when the stress disturbance parameter is greater than the fourth calibration threshold, the road segment condition change point in the target road segment ahead is determined.

[0012] Preferably, the method further includes a time delay learning step, which includes the following steps: step S601, monitoring the actual pressure build-up delay of the hydraulic braking actuator and calculating the differential increment between the actual pressure build-up delay and the nominal pressure response delay; step S602, updating the calibrated fluid mass transfer delay constant stored in the register according to the differential increment.

[0013] Preferably, step S202 includes the following sub-steps: step S2021, establishing an inverse correspondence between the change in driving torque and the change in braking pressure; step S2022, increasing the torque attenuation slope with a fixed step size, and simultaneously increasing the wheel cylinder pressure value according to the inverse correspondence, until the longitudinal residual value is less than or equal to the second calibration threshold.

[0014] Preferably, step S103 includes the following sub-steps: step S1034, subtracting the sum of the actual voltage build-up delay and the bus transmission delay from the control reference time to establish the first trigger time; step S1035, subtracting the sum of the torque response delay and the bus transmission delay from the control reference time to establish the second trigger time.

[0015] Preferably, after step S104, the method further includes the following steps: Step S105, after the control reference time, the wheel slip ratio is monitored in real time; when the wheel slip ratio exceeds the calibrated safe range, the torque gain of the drive torque adjustment unit and the pressure gain of the hydraulic brake actuator are adjusted so that the wheel slip ratio returns to the calibrated safe range.

[0016] A vehicle driving cooperative control system based on road segment information analysis, which is used to implement a vehicle driving cooperative control method based on road segment information analysis, includes: The vehicle joint control unit is communicatively connected to the hydraulic brake actuator and the drive torque adjustment unit, respectively. The vehicle joint control unit includes a parameter acquisition and gradient calculation module, which is used to acquire the segmented geometric feature parameters of the target road segment ahead and the driving state parameters of the current vehicle, and calculate the expected force gradient of the target road segment ahead relative to the current vehicle position based on the segmented geometric feature parameters and the driving state parameters. The mutation point establishment and benchmark prediction module is used to establish the road section condition mutation point when the expected force gradient is greater than the first calibration threshold, and predict the control benchmark time when the wheel touches the road section condition mutation point based on the current vehicle speed. The delay calculation and trigger establishment module is used to calculate the actual pressure build-up delay of the hydraulic brake actuator based on the control reference time, the real-time temperature of the brake pipeline of the hydraulic brake actuator, and the calibrated fluid mass transfer delay constant, combined with the brake gap elimination time and bus transmission delay. It also compares the torque response delay of the drive torque adjustment unit to establish the first trigger time for eliminating the brake friction pair gap and the second trigger time for adjusting the output torque. The collaborative control module is used to control the hydraulic brake actuator to implement brake pre-pressure build-up at the first trigger moment, and to control the drive torque adjustment unit to reduce the output torque at the second trigger moment, so that the end point of the actual pressure build-up delay of the hydraulic brake actuator and the end point of the torque response delay of the drive torque adjustment unit coincide at the control reference moment.

[0017] Compared with existing technologies, the vehicle driving cooperative control method based on road segment information analysis of the present invention has the following advantages: 1. In vehicle driving cooperative control, the desired gradient of path force is established by the road segment geometry and driving state. When the gradient exceeds the preset drastic change threshold, a hydraulic viscosity temperature correction coefficient and dynamic bus delay are introduced to rearrange the transmission sequence of drive and braking commands. Relying on the cascade rearrangement of the first trigger moment and the second trigger moment belonging to the power subsystem, the brake wheel cylinder eliminates the mechanical gap of the friction pair and maintains the critical contact state before the vehicle reaches the point of drastic change in attributes. This ensures that the starting point of drive motor torque decay and the starting point of brake pressure rise are completely coincided when the wheel reaches the point of sudden change in road conditions, thereby achieving coordinated control of drive torque and braking pressure and eliminating torque vacuum and parasitic resistance caused by the asymmetry of physical response of discrete subsystems.

[0018] 2. During the transitional conditions when the vehicle passes through a region of drastic attribute changes, the vehicle joint control unit collects the actual longitudinal acceleration at high frequency to establish a residual value with the desired longitudinal acceleration. When the residual value exceeds the threshold, the adaptive correction operator is activated. The drive motor torque attenuation slope and the brake wheel cylinder pressure value are finely adjusted through cascaded stepping until the residual value converges to the preset range. This feedback adjustment converts component wear and mass transfer resistance degradation into closed-loop control parameters. Relying on the online rolling update of the ratio between drive torque and braking pressure, the transient deceleration response of the vehicle approaches the target desired trajectory, suppressing cross-domain resistance interference caused by mechanical degradation.

[0019] 3. Under conditions of sudden changes in local road surface or severe oscillations caused by bus signal interference, the vehicle joint control unit samples the desired force gradient at a fixed period. When the oscillation amplitude of the gradient exceeds the interference threshold in multiple consecutive periods, it triggers the sliding degradation bottom-up control. The system cuts off the continuous adaptive adjustment loop, keeps the torque attenuation slope of the motor at a fixed value, and synchronously controls the brake wheel cylinder pressure to maintain a preset constant pressure state. This hardening control mechanism blocks the impact of high-frequency random noise on the power and braking subsystems by constructing a defined physical boundary, suppresses frequent commutation switching of heterogeneous actions, and reduces the wear of hydraulic regulating valves and inverter power devices. Attached Figure Description

[0020] Figure 1 This is a flowchart of the vehicle driving cooperative control method based on road segment information analysis of the present invention; Figure 2 This is a structural diagram of the vehicle driving cooperative control system based on road segment information analysis of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0022] A vehicle driving cooperative control method based on road segment information analysis includes the following steps: Step S101: Obtain the segmented geometric feature parameters of the target road segment ahead and the driving state parameters of the current vehicle, and calculate the expected force gradient of the target road segment ahead relative to the current vehicle position based on the segmented geometric feature parameters and the driving state parameters. Step S102: When the expected gradient of the force is greater than the first calibration threshold, the road section working condition change point is established, and the control reference time when the wheel touches the road section working condition change point is predicted based on the current vehicle speed. Step S103: Based on the control reference time, according to the real-time temperature of the brake pipeline of the hydraulic brake actuator and the calibrated fluid mass transfer delay constant, the actual pressure build-up delay of the hydraulic brake actuator is calculated in combination with the brake gap elimination time and the bus transmission delay. The torque response delay of the drive torque adjustment unit is compared with that of the drive torque adjustment unit to establish the first trigger time for eliminating the brake friction pair gap and the second trigger time for adjusting the output torque. Step S104: At the first trigger moment, control the hydraulic braking actuator to perform braking pre-pressure build-up, and at the second trigger moment, control the drive torque adjustment unit to reduce the output torque, so that the end point of the actual pressure build-up delay of the hydraulic braking actuator and the end point of the torque response delay of the drive torque adjustment unit coincide at the control reference moment.

[0023] Preferably, after the vehicle enters the point of sudden change in road conditions, the following steps are also included: Step S201, obtain the current vehicle's true longitudinal acceleration and calculate the longitudinal residual value between the true longitudinal acceleration and the expected longitudinal acceleration; Step S202, when the longitudinal residual value is greater than the second calibration threshold, adjust the torque attenuation slope of the drive torque adjustment unit and the wheel cylinder pressure value of the hydraulic brake execution unit until the longitudinal residual value is less than or equal to the second calibration threshold.

[0024] Preferably, the method further includes the following steps: step S301, sampling the expected force gradient at a fixed period and monitoring the oscillation amplitude of the expected force gradient on the time axis; step S302, when the oscillation amplitude is greater than the third calibration threshold in multiple consecutive sampling periods, stabilizing the torque attenuation slope of the driving torque adjustment unit within the first calibration range, and stabilizing the wheel cylinder pressure of the hydraulic brake actuator within the second calibration range.

[0025] Preferably, the method for calculating the actual pressure build-up delay in step S103 includes the following steps: Step S1031, determining the hydraulic viscosity correction coefficient based on the real-time temperature of the brake pipeline of the hydraulic brake actuator, wherein the hydraulic viscosity correction coefficient is inversely proportional to the real-time temperature; Step S1032, multiplying the calibrated fluid mass transfer delay constant by the hydraulic viscosity correction coefficient to obtain the corrected fluid mass transfer delay; Step S1033, adding the corrected fluid mass transfer delay to the brake gap elimination time and the bus transmission delay to obtain the actual pressure build-up delay.

[0026] Preferably, the segmented geometric feature parameters in step S101 include the slope variation rate and the road surface adhesion coefficient variation rate. The method for determining the road segment condition change point in step S102 includes the following steps: Step S1021, weighted summation of the slope variation rate and the road surface adhesion coefficient variation rate to obtain the stress disturbance parameter; Step S1022, when the stress disturbance parameter is greater than the fourth calibration threshold, the road segment condition change point in the target road segment ahead is determined.

[0027] Preferably, the method further includes a time delay learning step, which includes the following steps: step S601, monitoring the actual pressure build-up delay of the hydraulic braking actuator and calculating the differential increment between the actual pressure build-up delay and the nominal pressure response delay; step S602, updating the calibrated fluid mass transfer delay constant stored in the register according to the differential increment.

[0028] Preferably, step S202 includes the following sub-steps: step S2021, establishing an inverse correspondence between the change in driving torque and the change in braking pressure; step S2022, increasing the torque attenuation slope with a fixed step size, and simultaneously increasing the wheel cylinder pressure value according to the inverse correspondence, until the longitudinal residual value is less than or equal to the second calibration threshold.

[0029] Preferably, step S103 includes the following sub-steps: step S1034, subtracting the sum of the actual voltage build-up delay and the bus transmission delay from the control reference time to establish the first trigger time; step S1035, subtracting the sum of the torque response delay and the bus transmission delay from the control reference time to establish the second trigger time.

[0030] Preferably, after step S104, the method further includes the following steps: Step S105, after the control reference time, the wheel slip ratio is monitored in real time; when the wheel slip ratio exceeds the calibrated safe range, the torque gain of the drive torque adjustment unit and the pressure gain of the hydraulic brake actuator are adjusted so that the wheel slip ratio returns to the calibrated safe range.

[0031] A vehicle driving cooperative control system based on road segment information analysis, which is used to implement a vehicle driving cooperative control method based on road segment information analysis, includes: The vehicle joint control unit is communicatively connected to the hydraulic brake actuator and the drive torque adjustment unit, respectively. The vehicle joint control unit includes a parameter acquisition and gradient calculation module, which is used to acquire the segmented geometric feature parameters of the target road segment ahead and the driving state parameters of the current vehicle, and calculate the expected force gradient of the target road segment ahead relative to the current vehicle position based on the segmented geometric feature parameters and the driving state parameters. The mutation point establishment and benchmark prediction module is used to establish the road section condition mutation point when the expected force gradient is greater than the first calibration threshold, and predict the control benchmark time when the wheel touches the road section condition mutation point based on the current vehicle speed. The delay calculation and trigger establishment module is used to calculate the actual pressure build-up delay of the hydraulic brake actuator based on the control reference time, the real-time temperature of the brake pipeline of the hydraulic brake actuator, and the calibrated fluid mass transfer delay constant, combined with the brake gap elimination time and bus transmission delay. It also compares the torque response delay of the drive torque adjustment unit to establish the first trigger time for eliminating the brake friction pair gap and the second trigger time for adjusting the output torque. The collaborative control module is used to control the hydraulic brake actuator to implement brake pre-pressure build-up at the first trigger moment, and to control the drive torque adjustment unit to reduce the output torque at the second trigger moment, so that the end point of the actual pressure build-up delay of the hydraulic brake actuator and the end point of the torque response delay of the drive torque adjustment unit coincide at the control reference moment.

[0032] Example 1: In a vehicle cross-domain cooperative control scenario involving continuous operation and drastic changes in road attributes, the vehicle travels at a constant speed of 100 km / h. Onboard sensors detect the target road segment ahead in real time. When the sensors detect a road segment with a sudden increase in gradient and a decrease in road surface adhesion coefficient, the vehicle joint control unit, based on the geometric feature parameters of the target road segment ahead collected by the onboard data bus, including the path gradient and road surface adhesion coefficient, simultaneously collects the current driving state parameters, namely longitudinal speed and longitudinal position. The geometric feature parameters and driving state parameters are then input into the vehicle's longitudinal dynamic constraint model to calculate the expected force gradient of the target path. In this invention, the longitudinal dynamic constraint model of the vehicle body is constructed based on the force balance equation of the whole vehicle, which specifically incorporates slope information. Converted into ramp resistance The road surface adhesion coefficient Mapped to the maximum available ground braking force limit, combined with the current total mass of the vehicle. Rolling resistance coefficient Including wind resistance loss, output the expected longitudinal force of the vehicle at a specific coordinate point. The calculation formula is expressed as follows: ,in, This is the wheel-end driving force converted from the current driving torque. This is the drag coefficient. For windward area, air density, The longitudinal vehicle speed; therefore, the model compares the preceding slice node with the current position. The difference is used to obtain the expected force gradient, which reflects the severity of the sudden change in environmental load. The expected longitudinal force abrupt change rate of the vehicle caused by the external environment when the vehicle enters a road section with changing properties is expressed by the following formula: ,in, The expected longitudinal force on the vehicle at the predicted slice node ahead. Let the expected longitudinal force be the force on the vehicle at its current longitudinal position coordinate. The increment of the spatial distance between the current longitudinal position coordinates and the predicted slice node is calculated based on the desired force gradient. When the absolute value exceeds the preset drastic change threshold of 613 N / m, this preset drastic change threshold of 613 N / m is based on the vehicle maintaining a longitudinal impact force of less than [a certain value] at typical vehicle speeds. The comfort boundary is determined by reverse engineering. When the disturbance gradient generated by the stress environment exceeds this limit, the feedback adjustment of a single subsystem alone is no longer sufficient to suppress the longitudinal acceleration fluctuations caused by the response delay. The cross-domain timing advance hedging mechanism intervenes to ensure the stability of the vehicle dynamics. The vehicle joint control unit determines that the working condition ahead is a condition of drastic change in road attributes and triggers the cross-domain actuator timing coordination alignment program. The control unit retrieves the braking system basic clearance cross-period stored in the internal register. The nominal torque response delay of the power subsystem And read the dynamic communication bus delay determined by the current queued frame number of the vehicle network controller local area bus. Simultaneously, the control unit extracts the real-time temperature value output by the brake fluid line temperature sensor and uses a preset temperature-flow resistance mapping table to match the corresponding hydraulic viscosity correction coefficient. The temperature-flow resistance mapping table is calibrated based on experimental data of the dynamic viscosity of a specific type of brake fluid at different temperatures. It reflects the physical characteristic that the increased viscosity of the oil at low temperatures leads to an increase in mass transfer resistance; for example, at a standard ambient temperature of 25°C, The value is 1.0; at a low temperature of -20℃, the viscosity increases dramatically. The value is selected as 1.5; however, at a high temperature of 80℃, due to the increased fluidity of the oil, The value is reduced accordingly to 0.85; the control unit performs linear interpolation in the table using real-time temperature values ​​to obtain the current correction coefficient; the vehicle joint control unit calculates the collaborative pre-alignment time based on the above parameters. The calculation rules are as follows: ,in, The hydraulic viscosity correction factor is the preset pipeline fluid mass transfer delay constant at standard temperature. As the real-time temperature decreases, the pressure increases monotonically. Through the pre-pressure build-up action issued at the first trigger moment, the operating point of the hydraulic braking system is adjusted from the nonlinear gap elimination zone to the quasi-linear pressure rise zone. Since the brake friction pair has reached a critical contact state through a pre-charge pressure of 0.32 bar to 0.35 bar at the first trigger moment, the high-dimensional nonlinear time delay fluctuations caused by piston free stroke and seal deformation are eliminated. This makes the subsequent pressure jump at the control reference moment exhibit a highly predictable linear characteristic, thereby ensuring the alignment accuracy of the cascaded timing rearrangement based on linear addition and subtraction at the physical level. Calculations show that the collaborative pre-alignment time in this embodiment... The calculation result is 35ms. The vehicle joint control unit executes timing alignment based on the signal transmission and physical execution chain. It is modeled based on the physical signal transmission characteristics of the vehicle bus and the dynamic laws of fluid in the pipeline. The first trigger time is... With the second trigger moment Based on the predicted control reference time Reverse arrangement from the origin, Used to define the command issuance point of the hydraulic brake actuator, through calculation It is confirmed that, among them, The time required for the brake caliper to overcome the return spring tension and complete the stroke coverage is typically between 20 and 30 ms. The transmission cycle of the vehicle bus under the current communication load is determined by monitoring the average queuing delay of data packets in the bus controller. Used to limit the command issuance point of the drive torque adjustment unit, through calculation Confirmed, among which To mitigate the physical response delay from when the electric drive controller receives a command to when the inverter completes the current switching, the response differences of heterogeneous actuators are incorporated into a unified time base, ensuring that the starting point of hydraulic pressure build-up and the starting point of motor torque unloading are within the same time frame. Physically coincident at all times.

[0033] The vehicle joint control unit uses the predicted moment when the vehicle's wheel tracks reach the point of drastic change in the target road segment's attributes as the control reference zero point, and performs a reverse countdown sequence on the forward time axis, advancing the reverse time sequence to the first trigger moment. At that time, the control unit sends a pre-pressure build-up control data packet to the hydraulic adjustment mechanism of the braking subsystem, at the first trigger moment. The calculation rules are as follows: At this moment, the hydraulic adjustment mechanism responds to the pre-pressure control data packet, driving the hydraulic source to inject the target pre-charge pressure of 0.32 bar into the brake wheel cylinder. This target pre-charge pressure acts on the brake piston, overcoming and eliminating the physical-mechanical clearance of 0.14 mm between the brake caliper and brake disc before the vehicle reaches the point of drastic change in properties. This ensures that the friction pairs of the braking subsystem are in a critical working state where they are in close contact and do not generate braking torque. When the reverse time sequence advances to the second trigger moment... At that time, the control unit sends a torque decay control command to the electric drive controller of the power subsystem, at the second trigger moment. Stiffness equals the nominal torque response delay of the dynamic subsystem The electric drive controller adjusts the switching duty cycle of the inverter semiconductor power devices, and drives the power source to unload energy according to the preset torque decay slope. Through the above nonlinear cascade timing rearrangement, the starting inflection point of the torque decrease of the power source and the starting inflection point of the pressure jump of the brake wheel cylinder are completely coincided at the moment when the vehicle reaches the point of drastic change in attributes.

[0034] Within the transition region after the vehicle passes the point of dramatic attribute change, the vehicle joint control unit reads the actual longitudinal acceleration output by the onboard longitudinal accelerometer with a control cycle of 12ms. And calculate its relationship with the current desired longitudinal acceleration. The acceleration residual value is used to determine the dynamic torque imbalance of the cross-domain actuator during vehicle passage through a rapidly changing region. When the absolute value of the acceleration residual value does not exceed 0.23 m / s², the system maintains the current feedforward control state. When the absolute value of the acceleration residual value exceeds 0.23 m / s², the system determines that there is a dynamic torque imbalance in the cross-domain actuator. The vehicle joint control unit activates the adaptive correction operator and establishes an inverse mapping between the driving torque variation and the braking pressure variation based on the vehicle's longitudinal dynamic force balance equation. The vehicle's acceleration stability during transients of operating condition switching depends on the continuity of the total wheel-end torque. Real-time signals from the drive motor rotor position sensor and the brake line pressure sensor are collected to calculate the compensation coefficient for the braking pressure demand caused by the increase in driving torque. , The determination steps include: when the vehicle is in a constant-speed coasting condition, periodically adjusting the output torque of the drive motor and simultaneously adjusting the brake wheel cylinder pressure, recording the ratio of torque change to pressure change while maintaining constant longitudinal acceleration, and during correction, if an acceleration residual value is detected... Exceeding the preset control boundary, according to the formula Calculate the required pressure correction amount, and reduce the equivalent driving torque command value according to the reverse correspondence, where, For the overall vehicle quality, The effective radius of the wheel, The structural constant formed by the friction coefficient of the brake disc and the piston area of ​​the caliper is used. Through real-time coupling of physical parameters, the unloading rate of the driving energy and the increase rate of the braking pressure are offset on the energy gradient. When the residual value is greater than 0 and the absolute value exceeds 0.23 m / s², the control unit increases the actual torque attenuation slope of the power source in cascaded steps of 5 Nm / ms and simultaneously issues a pressure adjustment command to control the hydraulic adjustment mechanism to increase the target pressure value of the brake wheel cylinder in pressure steps of 0.12 bar. The system continuously cycles the above correction action until the absolute value of the acceleration residual converges to within 0.04 m / s². The convergence accuracy of 0.04 m / s² benefits from the 12 ms high-frequency control cycle used in this invention. This cycle is much smaller than the mechanical response constant of the braking actuator, ensuring that the adaptive correction operator can complete multiple closed-loop iterations before the acceleration fluctuation evolves into a large impact. Combined with the linear pressure response characteristics formed by the aforementioned pre-built pressure, the system has sufficient control bandwidth to achieve rapid convergence of the residual. During the above correction execution process, if the vehicle joint control unit detects the desired force gradient... When the system exhibits non-monotonic oscillations over three consecutive sampling periods and the absolute value of the oscillation amplitude exceeds 815 N / m, the control unit cuts off the adaptive proportional adjustment logic, rigidly locks the torque decay slope of the power source to 50 Nm / s, and maintains the target pressure of the brake wheel cylinder at 0.41 bar until the desired force gradient is reached. The oscillation amplitude dropped to below 500 N / m.

[0035] Example 2: To verify the engineering practicality of a vehicle driving cooperative control method based on road segment information analysis under complex dynamic conditions, the experiment was conducted on a hardware-in-the-loop simulation test platform. The main control unit of the test platform was configured as a real-time processor, which has a 10kHz sampling frequency and a deterministic instruction execution delay of less than 0.1ms. The test scenario was set as a target vehicle entering a road segment with continuously changing slope and abrupt changes in road surface adhesion coefficient at a base speed of 80km / h. Two working condition nodes were set in the experiment: node A showed an increase in path slope from 3% to 8%, and node B showed a step decrease in road surface adhesion coefficient from 0.8 to 0.3. The experimental design included three sample groups with differentiated characteristics for comparative demonstration. The first group was a control sample group using existing technology control logic, which only calculated the target vehicle speed based on the road segment slope and did not perform cross-domain timing alignment; the second group was the sample group of the present invention, which adopted... The same cross-domain collaborative control scheme as in Example 1 was used, and all action steps, including pre-build-up pressure timing and adaptive correction of torque decay slope, were fully executed. The third group was the parameter out-of-range control group, whose torque decay slope was set to 150 Nm / s, exceeding the upper limit boundary of the system to maintain power output stability under the current working condition. This simulated the system performance under non-optimal parameter configuration. During the test, the data acquisition unit recorded the vehicle longitudinal acceleration, drive motor torque, and brake wheel cylinder pressure at a sampling period of 10 ms. The following are the key performance data of each sample group when passing through working condition node A: The test data shows that due to the timing misalignment between the power subsystem and the braking subsystem, the longitudinal acceleration of the control sample group showed a negative step impact within the window of 50 ms to 150 ms after entering working condition node A, with the peak acceleration fluctuation reaching 0.58 m / s². Moreover, the starting point of the power source torque decrease lagged behind the starting point of the brake pressure increase by about 40 ms, resulting in a torque vacuum.

[0036] Under the same environmental conditions, the prototype of this invention, by executing a collaborative pre-alignment program, establishes the brake wheel cylinder pressure to a contact pressure of 0.35 bar 28ms before reaching the working condition node A. After triggering collaboration, the timing error between the starting point of the power source torque decay and the starting point of the brake pressure rise is 4ms. The power source output torque decreases at a preset torque decay slope, and the peak value of longitudinal acceleration fluctuation when the vehicle passes through the working condition node A is reduced to 0.11m / s². The system torque vacuum phenomenon is eliminated, demonstrating the suppression effect of cross-domain collaborative control on longitudinal acceleration impact. For the parameter out-of-range control group, when the torque decay slope is set to 150Nm / s, although the response speed is improved, the drive motor current oscillates significantly in the overload area after passing through the working condition node A. The acceleration residual value suddenly increases from 0.08m / s² to 0.45m / s². The system frequently activates the correction operator to forcibly smooth it out, causing control command jitter. This data performance confirms that the parameter working range defined by this invention is an effective window after engineering optimization. Deviating from this range will cause system stability degradation.

[0037] The experiment further recorded the acceleration residual convergence characteristics when passing through working condition node B. After triggering the adaptive correction operator, the absolute value of the acceleration residual in the sample group of this invention converged from an instantaneous 0.21 m / s² at a rate of 0.03 m / s² per cycle. Within 180 ms after passing through working condition node B, the residual value stabilized within 0.03 m / s². This data shows that the rolling update control strategy based on acceleration residuals can offset the dynamic response lag of the actuator and maintain the longitudinal dynamic consistency of the vehicle in road sections with sudden changes in adhesion coefficient. Based on the above comparative test results, the longitudinal acceleration impact index of the sample group of this invention is better than that of the control group under various working conditions. The technical solution of this invention eliminates the torque vacuum and parasitic resistance caused by the asymmetry of physical response by cascading the energy unloading process of the power actuator and the mechanical clearance elimination process of the braking actuator on the time axis, proving that the vehicle driving cooperative control method has engineering feasibility and technical superiority.

[0038] Example 3: This example combines Figures 1 to 2 This document describes a vehicle driving cooperative control method and system based on road segment information analysis, such as... Figure 1 As shown, in step S101, the segmented geometric feature parameters of the target road segment ahead and the driving state parameters of the current vehicle are obtained, and the expected force gradient of the target road segment ahead relative to the current vehicle position is calculated accordingly. Proceeding to step S102, when the expected force gradient is greater than the first calibration threshold, a sudden change point in the road segment's operating condition is established, and the control reference time when the wheel reaches the sudden change point in the road segment's operating condition is predicted based on the current vehicle speed. Next, step S103 is executed, using the control time as a reference, and based on the real-time temperature of the brake line and the fluid mass transfer delay constant, combined with the brake gap elimination time and bus transmission delay, the actual pressure build-up delay is calculated, and compared with the torque response delay, establishing the first trigger time for eliminating the brake friction pair gap and the second trigger time for adjusting the output torque. Finally, in step S104, at the first trigger time, the hydraulic brake actuator is controlled to implement pre-pressure build-up, and at the second trigger time, the drive torque adjustment unit is controlled to reduce the output torque, so that the end point of the actual pressure build-up delay coincides with the end point of the torque response delay at the control reference time.

[0039] like Figure 2As shown, the system as a whole consists of a sensing and input hardware array, a vehicle joint control unit hardware node, a drive torque adjustment unit hardware node, and a hydraulic brake execution unit hardware node. The sensing and input hardware array includes an onboard sensing system for analyzing road segment geometric attribute sequences, a brake fluid line temperature sensor for collecting real-time brake line temperature, an onboard longitudinal accelerometer for high-frequency acquisition of real longitudinal acceleration, and wheel speed sensors for monitoring wheel speeds before and after brake release. The data collected by the sensing and input hardware array is input to the vehicle joint control unit hardware node via the onboard data bus or controller local area bus, which serves as the physical network transmission medium. This vehicle joint control unit hardware node integrates a parameter acquisition and gradient calculation module, a mutation point establishment and benchmark prediction module, and a delay calculation and triggering module. The system includes a vehicle control module, a collaborative control module, and a vehicle longitudinal dynamics constraint model and register runtime library. The runtime library stores time delay constants, force disturbance parameters, and time offset matrices. The vehicle joint control unit hardware node further outputs commands downstream via a bus. The drive torque adjustment unit hardware node includes an electric drive controller to parse the torque control commands sent by the bus, inverter semiconductor power devices to adjust the switching duty cycle, and a power source drive motor to unload energy according to a preset torque decay slope. Simultaneously, the hydraulic brake execution unit hardware node includes a hydraulic adjustment mechanism to distribute pre-built pressure control data packets, brake lines and wheel cylinder pressure sources to transmit high-dimensional nonlinear hydraulic fluid energy, and brake caliper friction pair mechanical components to eliminate physical gaps and maintain a critical contact state.

[0040] Example 4: In situations where the vehicle is traveling at high speed and the road environment is unsteady, the roadside sensing device acquires the distribution of obstacles and the road surface friction state of the road segment ahead. The onboard sensing system parses this into a sequence of road segment geometric attributes and monitors the powertrain torque output and braking system hydraulic pressure in real time to address the problem of lag in the vehicle's longitudinal dynamic response caused by sudden changes in road surface friction. When the adhesion coefficient gradient of the sensed road segment exceeds the calibration threshold, the vehicle joint control unit constructs a timing matching matrix for powertrain unloading and hydraulic brake pressure build-up based on the current vehicle speed and the distance to the pre-aimed road segment. The joint control unit collects the brake line temperature signal in real time, updates the fluid mass transfer delay constant using the hydraulic viscosity mapping table, and dynamically calibrates the bus transmission delay according to the bus communication load state, thereby calculating the trigger time that meets the timing alignment requirements, including the cooperative pre-alignment time. Follow the calculation logic below: ,in, This is the period for eliminating brake system clearance. Let be the pipeline fluid mass transfer delay constant at standard temperature. This is the temperature-viscosity correction factor for the brake line; The nominal torque response delay of the power subsystem. This refers to the transmission delay of the real-time communication bus.

[0041] When the reverse timeline advances to the point where the first trigger moment is met... At the specified point, the vehicle's integrated control unit instructs the hydraulic braking system to perform pre-pressure build-up, increasing the wheel cylinder pressure to 0.35 bar by controlling the hydraulic source flow. Follow the timing constraints below: At this pressure level, the brake caliper friction pair eliminates mechanical clearance and is in a closed state, effectively reducing the pressure build-up dead zone of the braking system. When the reverse time axis advances to the second trigger moment... At this time, the power drive controller adjusts the switching duty cycle of the power devices to reduce the motor output torque. Equal to the nominal torque response delay of the power subsystem .

[0042] Through the aforementioned cascaded timing control, the torque unloading inflection point of the drive motor and the hydraulic brake pressure build-up inflection point are physically aligned at the abrupt change point of the target road segment, eliminating the torque vacuum in the transmission path. In the transition area after passing through the abrupt road segment, the vehicle joint control unit monitors the longitudinal acceleration residual with a control cycle of 12ms. When the absolute value of the acceleration residual exceeds the steady-state control boundary of 0.25m / s², the system activates the rolling correction operator. The control unit adjusts the motor torque attenuation slope in increments of 5Nm / ms and simultaneously adjusts the target pressure of the wheel cylinder in increments of 0.12bar. The above correction logic terminates when the acceleration residual converges to within 0.05m / s², thereby ensuring the smooth connection of longitudinal dynamic indicators when the vehicle crosses abrupt road segments and suppressing the longitudinal impact caused by the asymmetry of the actuator response.

[0043] Example 5: Before the vehicle enters a complex road section with frequent changes in gradient, the control system needs to complete the initial benchmark calibration for power response lag and braking system mass transfer delay. In the parked state after the vehicle is powered on, the control unit sends a pressure step command to the braking subsystem, monitors the initial fluctuation time of the longitudinal accelerometer output, and obtains the actual pressure build-up delay. And compare with the factory default parameters Calculate the time delay deviation This deviation is defined as the aging benchmark of the system's mechanical wear and hydraulic condition. The system uses it as the normal offset for timing compensation under subsequent operating conditions to ensure the stability of the collaborative alignment time during system operation. For operating conditions with drastic changes in road segment attributes, the vehicle joint control unit establishes a real-time monitoring logic for the expected force gradient based on the road segment's geometric parameters. The control unit collects the expected force gradient at a high frequency with a sampling period of 10ms. It also maintains a sliding time window of length 3 in the internal data buffer. If within 3 consecutive sampling periods, The absolute value of the signal exhibits non-monotonic oscillation with an amplitude exceeding 800 N / m. The system determines that there is environmental noise interference in the sensor data link and triggers a deterministic fallback control process. In this mode, the system departs from the closed-loop proportional correction path based on acceleration residuals, rigidly locks the torque unloading slope of the drive motor to 50 Nm / s, and forcibly maintains the pre-charge pressure of the brake wheel cylinder at a constant 0.4 bar. This establishes a definite torque control boundary in the noisy environment, eliminates the frequent switching between the power source and braking mechanism caused by high-frequency signal noise, and prevents wear of the actuator and dynamic oscillation caused by command mutual exclusion.

[0044] Example 6: Before the vehicle enters a complex road section with frequent changes in gradient, the vehicle's integrated control unit performs initial state calibration of the power actuator and braking actuator based on the parking condition. The integrated control unit cyclically sends preset pressure step commands to the braking actuator and monitors the speed change of the wheel speed sensor before and after pressure release to calculate the mechanical clearance of the braking system. The calculation logic is as follows: ,in, The effective moving speed of the braking piston. For the gap elimination period, This is the piston displacement coefficient generated per unit pressure.

[0045] The system is based on the mechanical clearance obtained from calibration. An initial synchronization lookup table for power response and braking pressure build-up was established. To address the mechanical characteristic drift of the braking subsystem after long-term operation, mechanical clearance and critical pressure were calibrated online during the vehicle's power-on self-test phase. Based on the linear mapping relationship between piston stroke and hydraulic volume, the inflection point of the hydraulic source output flow and pressure rise slope was monitored to locate the friction pair's contact state. The vehicle's joint control unit drove the hydraulic pump at a constant flow rate. Oil is injected into the wheel cylinder, and pressure sensor values ​​are collected in real time. During the piston's idle stroke, the pressure rise slope is... Maintaining within the nominal range; when the friction pairs are physically engaged, the system stiffness suddenly increases. Once the preset mutation threshold is exceeded, the time taken from the start of oil injection to the point of slope mutation is recorded. Determine the gap elimination period under the current environment. The steady-state pressure value at this point is calculated as the target pre-charge pressure. The calibration value is stored in a register as an offset, which is used to correct the first trigger moment in real time. In Parameters that compensate for the expansion of mechanical clearance caused by brake pad wear. This table uses temperature as an index to store the hydraulic system pressure build-up delay correction amount at different ambient temperatures. When the vehicle reaches the target road section, the vehicle's integrated control unit uses the real-time ambient temperature output by the external ambient temperature sensor. The current correction amount is located in the lookup table using a linear interpolation algorithm. This correction is used to compensate for the impact of hydraulic oil viscosity changes on braking response. The control unit inputs this calibration value into the cross-domain timing alignment logic to correct the sending timing of the power source torque attenuation command and the braking pressure jump command, thereby controlling the cross-domain action timing error within 2ms.

[0046] During system online operation, the vehicle joint control unit maintains a circular queue storing the most recent 50 sets of operating condition records for sensor data drift self-calibration. If a continuous steady-state deviation is detected between the powertrain output torque and the actual observed torque at the wheel ends, the system will take action. And satisfy: ,in, The number of samples collected; To output torque for the power subsystem, To measure the wheel-end torque, the system determines the steady-state deviation as the wear attenuation parameter of the actuator and introduces it as an online calibration bias into the subsequent torque control loop to achieve rolling compensation of the power output characteristics and ensure the accuracy of the vehicle driving control method under all operating conditions.

[0047] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit of this application and the scope of protection of this invention, and all of these forms are within the protection scope of this application.

Claims

1. A vehicle driving cooperative control method based on road segment information analysis, characterized in that, Includes the following steps: Step S101: Obtain the segmented geometric feature parameters of the target road segment ahead and the driving state parameters of the current vehicle, and calculate the expected force gradient of the target road segment ahead relative to the current vehicle position based on the segmented geometric feature parameters and the driving state parameters. Step S102: When the expected gradient of the force is greater than the first calibration threshold, the road section working condition change point is established, and the control reference time when the wheel touches the road section working condition change point is predicted based on the current vehicle speed. Step S103: Based on the control reference time, according to the real-time temperature of the brake pipeline of the hydraulic brake actuator and the calibrated fluid mass transfer delay constant, the actual pressure build-up delay of the hydraulic brake actuator is calculated in combination with the brake gap elimination time and the bus transmission delay. The torque response delay of the drive torque adjustment unit is compared with that of the drive torque adjustment unit to establish the first trigger time for eliminating the brake friction pair gap and the second trigger time for adjusting the output torque. Step S104: At the first trigger moment, control the hydraulic braking actuator to perform braking pre-pressure build-up, and at the second trigger moment, control the drive torque adjustment unit to reduce the output torque, so that the end point of the actual pressure build-up delay of the hydraulic braking actuator and the end point of the torque response delay of the drive torque adjustment unit coincide at the control reference moment.

2. The vehicle driving cooperative control method based on road segment information analysis according to claim 1, characterized in that, After the vehicle enters the point of sudden change in road conditions, the following steps are also included: Step S201, obtain the current vehicle's true longitudinal acceleration and calculate the longitudinal residual value between the true longitudinal acceleration and the expected longitudinal acceleration; Step S202, when the longitudinal residual value is greater than the second calibration threshold, adjust the torque attenuation slope of the drive torque adjustment unit and the wheel cylinder pressure value of the hydraulic brake execution unit until the longitudinal residual value is less than or equal to the second calibration threshold.

3. The vehicle driving cooperative control method based on road segment information analysis according to claim 1, characterized in that, The method further includes the following steps: Step S301, sampling the expected force gradient at a fixed period and monitoring the oscillation amplitude of the expected force gradient on the time axis; Step S302, when the oscillation amplitude is greater than the third calibration threshold in multiple consecutive sampling periods, stabilizing the torque attenuation slope of the driving torque adjustment unit within the first calibration range, and stabilizing the wheel cylinder pressure of the hydraulic brake actuator within the second calibration range.

4. The vehicle driving cooperative control method based on road segment information analysis according to claim 1, characterized in that, The method for calculating the actual pressure build-up delay in step S103 includes the following steps: Step S1031, determining the hydraulic viscosity correction coefficient based on the real-time temperature of the brake pipeline of the hydraulic brake actuator, wherein the hydraulic viscosity correction coefficient is inversely proportional to the real-time temperature; Step S1032, multiplying the calibrated fluid mass transfer delay constant by the hydraulic viscosity correction coefficient to obtain the corrected fluid mass transfer delay; Step S1033, adding the corrected fluid mass transfer delay to the brake gap elimination time and the bus transmission delay to obtain the actual pressure build-up delay.

5. The vehicle driving cooperative control method based on road segment information analysis according to claim 1, characterized in that, The segmented geometric feature parameters in step S101 include the slope variation rate and the road surface adhesion coefficient variation rate. The method for determining the road section working condition change point in step S102 includes the following steps: Step S1021, weighted summation of the slope variation rate and the road surface adhesion coefficient variation rate to obtain the stress disturbance parameter; Step S1022, when the stress disturbance parameter is greater than the fourth calibration threshold, the road section working condition change point in the target road section ahead is determined.

6. The vehicle driving cooperative control method based on road segment information analysis according to claim 1, characterized in that, The method also includes a time delay learning step, which includes the following steps: Step S601, monitoring the actual pressure build-up delay of the hydraulic braking actuator and calculating the differential increment between the actual pressure build-up delay and the nominal pressure response delay; Step S602, updating the calibrated fluid mass transfer delay constant stored in the register according to the differential increment.

7. The vehicle driving cooperative control method based on road segment information analysis according to claim 2, characterized in that, Step S202 includes the following sub-steps: Step S2021, establish the inverse correspondence between the driving torque variation and the braking pressure variation; Step S2022, increase the torque attenuation slope with a fixed step size, and simultaneously increase the wheel cylinder pressure value according to the inverse correspondence until the longitudinal residual value is less than or equal to the second calibration threshold.

8. The vehicle driving cooperative control method based on road segment information analysis according to claim 1, characterized in that, Step S103 includes the following sub-steps: Step S1034, subtract the sum of the actual voltage build-up delay and the bus transmission delay from the control reference time to establish the first trigger time; Step S1035, subtract the sum of the torque response delay and the bus transmission delay from the control reference time to establish the second trigger time.

9. The vehicle driving cooperative control method based on road segment information analysis according to claim 1, characterized in that, After step S104, the method further includes the following steps: Step S105, after the control reference time, the wheel slip ratio is monitored in real time; when the wheel slip ratio exceeds the calibrated safe range, the torque gain of the drive torque adjustment unit and the pressure gain of the hydraulic brake actuator are adjusted so that the wheel slip ratio returns to the calibrated safe range.

10. A vehicle driving cooperative control system based on road segment information analysis, used to implement the vehicle driving cooperative control method based on road segment information analysis as described in claim 1, characterized in that, include: The vehicle integrated control unit is communicatively connected to the hydraulic brake actuator and the drive torque adjustment unit, respectively. The vehicle joint control unit includes a parameter acquisition and gradient calculation module, which is used to acquire the segmented geometric feature parameters of the target road segment ahead and the driving state parameters of the current vehicle, and calculate the expected force gradient of the target road segment ahead relative to the current vehicle position based on the segmented geometric feature parameters and driving state parameters. The mutation point establishment and benchmark prediction module is used to establish the road section condition mutation point when the expected force gradient is greater than the first calibration threshold, and predict the control benchmark time when the wheel touches the road section condition mutation point based on the current vehicle speed. The delay calculation and trigger establishment module is used to calculate the actual pressure build-up delay of the hydraulic brake actuator based on the control reference time, the real-time temperature of the brake pipeline of the hydraulic brake actuator, and the calibrated fluid mass transfer delay constant, combined with the brake gap elimination time and bus transmission delay. It also compares the torque response delay of the drive torque adjustment unit to establish the first trigger time for eliminating the brake friction pair gap and the second trigger time for adjusting the output torque. The collaborative control module is used to control the hydraulic brake actuator to implement brake pre-pressure build-up at the first trigger moment, and to control the drive torque adjustment unit to reduce the output torque at the second trigger moment, so that the end point of the actual pressure build-up delay of the hydraulic brake actuator and the end point of the torque response delay of the drive torque adjustment unit coincide at the control reference moment.

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